Delhi is facing a very high-level pollution, with visibility so low that several flights had to be cancelled or diverted. The Air Quality Index was recorded above 900 in some places, when an AQI above 150 is considered unhealthy. And for a change, Diwali crackers are not being responsible for this dangerous pollution. Almost everyone has agreed that stubble burning by farmers in the nearby states, mainly in Punjab and Haryana, is the primary reason.
But this has raised a question in the mind of many people, why suddenly this problem of stubble burning aggravated so much to cause such huge pollution. Farmers must have been burning crop residue for decades, why this problem didn’t occur earlier. Moreover, crop farming takes place in the entire country, but why only Delhi region faces this problem.
There are several factors which have contributed to the increase in air pollution due to stubble burning, contributed by several government policies relating to farming. The green revolution, started to end the food insecurity in the country, encouraged food grain farming, which means large areas of the country are used for farming of rice and wheat. Now India produces so much these grains that a lot of them lie rotting in FCI warehouses.
Apart from water from irrigation, farmers also use groundwater for the cultivation of water-intensive crops like paddy. Earlier, farmers in Punjab in Haryana used to plant paddy in April-May. But monsoon rains don’t start at this time, so farmers used to use groundwater. As power for farming has been made free, farmers used run the pumpsets drawing water from below the ground continuously.
This had led to the depletion of water table. To mitigate this problem, the states of Punjab and Haryana passed identical laws in 2009 delaying the sowing of rice crop. The Haryana Preservation of Subsoil Water Act, 2009 and The Punjab Preservation of Sub-soil Water Act-2009 determines the date when farmers can plant paddy. According to the acts, farmers are not allowed to sow nursery of paddy before 15th May, and they can’t transplant the paddy before 15th June. This ensures that the crop receives adequate rain and does not need groundwater.
Before the acts came into effect, the paddy planted in April-May was harvested in September-October, a time when wind keeps moving in and around Delhi. So even if the stubble was burnt earlier, it was flown away by the wind and didn’t create a smog. After the government delayed planting, its harvesting was pushed to October-November, when the wind becomes stationary. This means when farmers burn the husk, the smoke and ash remain suspended on air, creating smog.
The postponing the paddy season started another problem, it leaves little room for farmers to sow the rabi crop, which is mainly wheat in Punjab and Haryana. And as wheat can’t be planted on the ground with standing paddy stubbles, burning them is only the cheap option to remove them quickly. Earlier farmers had 1-2 months of gap between the top crops, so many of them had removed them instead of burning them. Removing the stubble and keeping them in the field improves the fertility of the soil, while burning them degrades the soil. But farmers still burn as they have no other option to start planting wheat on time.
Another reason is the increased mechanisation of farming in Punjab and Haryana compared with other regions. The combines, machines used to harvest the crop and separate the grains on the spot, only reap the grains, leaving the stalks of stubble standing in the field. When crop is harvested manually, the crop is cut much below, and it is taken out of the field for processing, therefore the not much stubble remains on the field.
Moreover, husk is fodder for cattle, so farmers harvest and stock it in other states, particularly in North-Eastern and Eastern states. Farmers harvest crop manually in these states, and as these states are hit by flood during monsoon, the harvested husk provides acts as feed for their livestock when the grazing fields are flooded.
These are the main reasons why the stubble burning has turned into such a grave problem in recent years, and why it is mostly localised to Northern India.
Punjab has made the use of Super Straw Management System (SMS) with the harvesters mandatory to prevent stubble burning. These machines, which can be attached with existing combines, cuts the stubble and spread it uniformly in the field, eliminating the need for burning them. But the implementation of this order has not been strict, and all farmers can’t afford them as they are costly. Moreover, there are not enough such machines in use at present to cover the entire area before the planting of wheat. Therefore, farmers burn the stubble despite it been made illegal as per law and imposition of fines for violating the law.
Other than the SMS machine, there are several other options available to deal with stubble without burning them. Some of them are, Happy seeder (which allows planting wheat on a field with standing stubble), Rotavator (used for land preparation and incorporation of crop stubble in the soil), Zero till seed drill (used for land preparations directly sowing of seeds in the previous crop stubble), Baler (used for collection of straw and making bales of the paddy stubble), Paddy Straw Chopper (cutting of paddy stubble for easily mixing with the soil), Reaper Binder (used for harvesting paddy stubble and making into bundles) etc. But these machines are costly, and farmers are not willing to spend money on them when they can easily get rid of the stubble by burning them. Government is providing subsidy for such crop residue management machinery, but more need to be done to encourage farmers to use them.